[The biological effect of tetrahydrobiopterin and its potential role in sepsis]

It is well known that overproduction of nitric oxide (NO) is the final common pathway in septic shock. Tetrahydrobiopterin (BH4), a low molecular weight pterdine, is an essential cofactor required for the activity of NO synthase (NOS). Existing evidences show that lipopolysaccharide and proinflammatory cytokines can cause significant rises in bipoterin levels, which in turn augments the synthesis of NO. Also inhibition of biosynthesis of BH4 can decrease NO formation, implying that BH4 may be involved in the pathophysiological alterations of sepsis. However, the precise mechanisms of BH4 in regulating NO formation are not yet fully understood. In this review, we focus on the biological effects and regulation of BH4, as well as its potential role in sepsis. The therapeutic significance of biopterin synthesis inhibitors in septic symptoms is also discussed.